From c3cee37add62572f9ba477c3e4df07f7942b09b3 Mon Sep 17 00:00:00 2001
From: William Brawner <me@wbrawner.com>
Date: Thu, 25 Nov 2021 06:58:47 -0700
Subject: [PATCH] Add models for recurring transactions

---
 .../recurringtransaction.ts                   | 197 ++++++++++++++++++
 1 file changed, 197 insertions(+)
 create mode 100644 src/app/recurringtransactions/recurringtransaction.ts

diff --git a/src/app/recurringtransactions/recurringtransaction.ts b/src/app/recurringtransactions/recurringtransaction.ts
new file mode 100644
index 0000000..901379a
--- /dev/null
+++ b/src/app/recurringtransactions/recurringtransaction.ts
@@ -0,0 +1,197 @@
+export class RecurringTransaction {
+  id: string = '';
+  title: string;
+  description: string = null;
+  frequency: Frequency;
+  start: Date = new Date();
+  end?: Date;
+  amount: number;
+  expense = true;
+  categoryId: string;
+  budgetId: string;
+  createdBy: string;
+}
+
+export class Frequency {
+  unit: FrequencyUnit;
+  count: number;
+  time: Time;
+  amount?: (void | Set<DayOfWeek> | DayOfMonth | DayOfYear);
+
+  private constructor(unit: FrequencyUnit, count: number, time: Time, amount?: (void | Set<DayOfWeek> | DayOfMonth | DayOfYear) = null) {
+    this.unit = unit;
+    this.count = count;
+    this.time = time;
+    this.amount = amount;
+  }
+
+  static Daily(count: number, time: Time): Frequency {
+    return new Frequency(FrequencyUnit.DAILY, count, time);
+  }
+
+  static Weekly(count: number, time: Time, daysOfWeek: Set<DayOfWeek>): Frequency {
+    return new Frequency(FrequencyUnit.WEEKLY, count, time, daysOfWeek)
+  }
+
+  static Monthly(count: number, time: Time, dayOfMonth: DayOfMonth): Frequency {
+    return new Frequency(FrequencyUnit.MONTHLY, count, time, dayOfMonth)
+  }
+
+  static Yearly(count: number, time: Time, dayOfYear: DayOfYear): Frequency {
+    return new Frequency(FrequencyUnit.YEARLY, count, time, dayOfYear)
+  }
+
+  static parse(s: string): Frequency {
+    const parts = s.split(';');
+    let count: number, time: Time;
+    switch (parts[0]) {
+      case 'D':
+        count = Number.parseInt(parts[1]);
+        time = Time.parse(parts[2]);
+        return this.Daily(count, time);
+      case 'W':
+        count = Number.parseInt(parts[1]);
+        time = Time.parse(parts[3]);
+        const daysOfWeek = new Set(parts[2].split(',').map(day => DayOfWeek[day]));
+        return this.Weekly(count, time, daysOfWeek);
+      case 'M':
+        count = Number.parseInt(parts[1]);
+        time = Time.parse(parts[3]);
+        const dayOfMonth = DayOfMonth.parse(parts[2]);
+        return this.Monthly(count, time, dayOfMonth);
+      case 'Y':
+        count = Number.parseInt(parts[1]);
+        time = Time.parse(parts[3]);
+        const dayOfYear = DayOfYear.parse(parts[2]);
+        return this.Yearly(count, time, dayOfYear);
+      default:
+        throw new Error(`Invalid Frequency format: ${s}`);
+    }
+  }
+}
+
+export enum FrequencyUnit {
+  DAILY = 'D',
+  WEEKLY = 'W',
+  MONTHLY = 'M',
+  YEARLY = 'Y',
+}
+
+export class Time {
+  hours: number;
+  minutes: number;
+  seconds: number;
+
+  constructor(hours: number, minutes: number, seconds: number) {
+    this.hours = hours;
+    this.minutes = minutes;
+    this.seconds = seconds;
+  }
+
+  toString(): string {
+    return [
+      String(this.hours).padStart(2, '0'),
+      String(this.minutes).padStart(2, '0'),
+      String(this.seconds).padStart(2, '0'),
+    ].join(':')
+  }
+
+  static parse(s: string): Time {
+    if (!s.match(/[0-9]{2}:[0-9]{2}:[0-9]{2}/) {
+      throw new Error('Invalid time format. Time must be formatted as HH:mm:ss');
+    }
+    const parts = s.split(':').map(part => Number.parseInt(part));
+    return new Time(parts[0], parts[1], parts[2]);
+  }
+}
+
+export enum Position {
+  DAY = 'DAY',
+  FIRST = 'FIRST',
+  SECOND = 'SECOND',
+  THIRD = 'THIRD',
+  FOURTH = 'FOURTH',
+  LAST = 'LAST',
+}
+
+export enum DayOfWeek {
+  MONDAY = 'MONDAY',
+  TUESDAY = 'TUESDAY',
+  WEDNESDAY = 'WEDNESDAY',
+  THURSDAY = 'THURSDAY',
+  FRIDAY = 'FRIDAY',
+  SATURDAY = 'SATURDAY',
+  SUNDAY = 'SUNDAY',
+}
+
+export class DayOfMonth {
+  position: Position;
+  day: (number | DayOfWeek);
+
+  private constructor(position: Position, day: (number | DayOfWeek)) {
+    this.position = position;
+    this.day = day;
+  }
+
+  static Each(day: number): DayOfMonth {
+    if (day < 1 || day > 31) {
+      throw new Error('Day must be between 1 and 31');
+    }
+    return new DayOfMonth(Position.DAY, day);
+  }
+
+  static PositionalDayOfWeek(position: Position, day: DayOfWeek): DayOfMonth {
+    if (position === Position.DAY) {
+      throw new Error('Use DayOfMonth.Each() to create a monthly recurring transaction on the same calendar day');
+    }
+    return new DayOfMonth(position, day)
+  }
+
+  static parse(s: string): DayOfMonth {
+    const parts = s.split('-');
+    const position = Position[parts[0]];
+    if (position === Position.DAY) {
+      return DayOfMonth.Each(Number.parseInt(parts[1]));
+    } else {
+      return DayOfMonth.PositionalDayOfWeek(position, DayOfWeek[parts[1]]);
+    }
+  }
+}
+
+export class DayOfYear {
+  month: number;
+  day: number;
+
+  constructor(month: number, day: number) {
+    this.month = month;
+    this.day = day;
+  }
+
+  static parse(s: string): DayOfYear {
+    if (!s.match(/[0-9]{2}-[0-9]{2}/)) {
+      throw new Error(`Invalid format for DayOfYear: ${s}`)
+    }
+    const parts = s.split('-').map(part => Number.parseInt(part));
+    if (parts[0] < 1 || parts[0] > 12) {
+      throw new Error(`Invalid month for DayOfYear: ${parts[0]}`);
+    }
+    let maxDay: number;
+    switch (parts[0]) {
+      case 2:
+        maxDay = 29;
+        break;
+      case 4:
+      case 6:
+      case 9:
+      case 11:
+        maxDay = 30;
+        break;
+      default:
+        maxDay = 31;
+    }
+    if (parts[1] < 1 || parts[1] > maxDay) {
+      throw new Error(`Invalid day for DayOfYear: ${parts[0]}`);
+    }
+    return new DayOfYear(parts[0], parts[1]);
+  }
+}
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